How to change partition size in Windows Server 2016?

All disk partitions are created when building the server, but the disk partitions may not meet your needs after running this server for a period of time. The typical disk space issue is C drive getting full, so there is not enough free space to keep server running smoothly. While in other computers there are different issue existing, for example: C drive was created too large when installing Windows, a data drive for backup becomes full, etc. Luckily, new technology makes it possible to change partition size without starting over.

Increase partition size

To change partition size on Windows Server 2016, there are two choices: Windows built-in Disk Management and 3rd-party partition software. The benefit of Disk Management is safe, it is able to shrink and extend volume on the fly. Meanwhile, it has many limitations. 3rd-party software is much powerful, but the precondition is selecting a reliable program. Otherwise, it may cause system boot failure or data loss.

As I said in the beginning, the aim to change partition size is different, in this article I can only list the common scenarios and corresponding solution.

Change partition size by Disk Management

From Windows Server 2008, Microsoft added Shrink Volume and Extend Volume. Windows Server 2016 inherited these functions, with which you can reduce and increase size of an existing volume.

Reduce partition size in DM


  1. Right-click Windows on bottom left and select “Disk Management“.
  2. Right-click C drive (or other one you want to shrink) and select “Shrink Volume…“.
  3. Type the value how much free space to shrink from it and click “Shrink” to process.

Free space shrink from this volume will be converted to Unallocated, which can be used to create new volumes.


  1. You cannot shrink a volume beyond the point where any unmovable files are located. (such as Paging file, Hibernation and other very large files)
  2. Unallocated space can only generated behind the volume you shrank.
  3. Unallocated space can only be used to create new volumes, it cannot be used to expand other existing volume.

Increase partition size in DM

Note: only when there is adjacent Unallocated space at the right side, you can increase partition size, steps:

  1. Right-click the partition you want to extend and select “Extend Volume…
  2. Extend Volume Wizard will be launched, click Next to continue.
  3. In next window, type the amount of free space to add to C drive and click Next.
  4. Confirm the operation and click “Finish” to process.


  1. FAT32 partition cannot be extended even if there is adjacent Unallocated space.
  2. To use Extend Volume, there must be adjacent Unallocated space at the right side.
  3. Unallocated space cannot be added into the adjacent volume at its right side.

In a word: in Server 2016 Disk Management, you can change partition size of a single volume, you cannot extend a volume by shrinking another volume.

Change partition size with partition software

Comparing with Disk Management, the main benefit of partition software is that you can shrink any volume to extend any other volume in the same disk. It is also much easier to operate, just click and drag.

Watch the video and you’ll know how easy it is to change partition size in Windows Server 2016:

Pay attention to data safety

As I said in the beginning, you’d better select a reliable partition software, otherwise it may cause server boot failure or data loss, why?

Many factors if cannot be handled by the software could cause data loss or partition corruption, for example: large amount of files in the partition that you want to change size, low server memory, high CPU usage rate, etc. Another risk that even Disk Management cannot handle is hardware issue such as power failure! You can image what happen if power failure when resizing partitions. If moving files or updating system information is not finished, of course Operating System cannot read the damaged information, it means partition corruption and data loss.

NIUBI Partition Editor is the ONLY software than can roll back the server to the status before resizing automatically and rapidly, if these issue occurred, so Operating System and data always keep intact. This is the reason why it is recommended as the safest partition software.

Furthermore, its unique file-moving algorithm helps resize partition 30 – 300% faster that other tools. In some situations such as very large amount of files or low server memory, it can be 500% faster!

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